A shareware game called begin was released in 1984: a tactical starship game with a good AI and fair rules (the computer had no advantage) I've hacked assembly code to make it a multiplayer game, so that folk can challenge each other rather than the AI.
Archverse is a massively multiplayer web based strategy game, that focuses on Combat, Diplomacy, Economics and Tactics.
Enhancements to NetHack v3.4, both to gameplay and to source/build structure.
Thanks to Rich Skrenta releasing the source in May 2009, there is now a chance for the rest of us to look at Olympia and maybe fix it up to run a game again.
Open Source Football is an American Football simulation game where users assume the role of Head Coach/GM/Owner and compete against each other in virtual football leagues.
This project is an as-yet unnamed hot-seat turn-based strategy game with elements of tribal conflict.
WetFire was is a basic text-based adventure game engine, written in C++. It was written as a learning experience to the programmer, so a lot of the code is messy and may not be safe for viewing.
Xenov will be a game engine capable of producing 3D/isometric games for both Windows and Linux. It will have many subapplications to form a complete production suite.